297 research outputs found
A novel elimination reaction catalysed by human alpha-methylacyl-CoA racemase (AMACR; P504S) and potential applications for measuring enzyme activity
A novel elimination reaction catalysed by human alpha-methylacyl-CoA racemase (AMACR; P504S) and potential applications for measuring enzyme activity
A novel elimination reaction catalysed by human alpha-methylacyl-CoA racemase (AMACR; P504S) and potential applications for measuring enzyme activity
A novel elimination reaction catalysed by human alpha-methylacyl-CoA racemase (AMACR; P504S) and potential applications for measuring enzyme activity
Pleiotropic Effects of the Trichloroethylene-Associated P81S VHL Mutation on Metabolism, Apoptosis, and ATM-Mediated DNA Damage Response
BackgroundThe risk relevance of the P81S von Hippel-Lindau (VHL) gene hotspot mutation identified in clear cell renal cell carcinoma from individuals exposed occupationally to trichloroethylene (TCE) is not known. VHL mutations in hereditary VHL syndrome strongly correlate with phenotypic associations, but specific sporadic mutations in VHL that uniquely alter its protein function may provide a selective growth advantage for somatic cells harboring these mutations.MethodsVHL deficient (Vhl -/-) mouse embryonic stem cells were generated that stably express wild-type, P81S, or R167Q human VHL protein. Under hypoxic conditions, cell lines were examined for hypoxia-inducible transcription factor family (HIF) stabilization and E3-ubiquitin ligase complex interactions. In vivo, teratomas were examined for tumor size, proliferation, apoptosis, and immunohistochemistry and subjected to gene expression analysis. Wild-type, R167Q, and P81S VHL-expressing teratomas were also exposed to 5 Gy ionizing radiation to quantify apoptotic response. Proliferation and apoptosis and teratoma growth were analyzed by either Student t test or analysis of variance with Bonferroni correction. All statistical tests were two-sided.ResultsThe P81S VHL mutation produces deregulation of HIF factors in cell culture but exhibits a growth advantage in the tumor microenvironment, in part because of suppression of apoptosis (P81S mean = 0.9%, 95% confidence interval = 0.6 to 1.2%; WT mean = 7.6%; 95% confidence interval = 6.4 to 8.8%; P < .001) coupled with sustained proliferation. Transcriptional analysis of P81S teratomas revealed the induction of metabolic pathways, antiapoptotic genes, and global suppression of key DNA damage response genes not observed in VHL wild-type or R167Q mutants. In vivo irradiation exposure showed that P81S mutant is resistant to ionizing radiationāinduced apoptosis.ConclusionsThe TCE-associated P81S VHL mutation can initiate a unique adaptive response required for selective tumor growth through pleiotropic effects on metabolic diversification, apoptosis suppression, and alteration of the DNA damage response
Synthesis and conformational and configurational studies of diastereoisomeric <i>O</i>-protected 4-(arylsulfonimidoyl)butane-1,2,3-triols
Cross-talk between epidermal growth factor receptor and protein kinase C during calcium-induced differentiation of keratinocytes
Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/74029/1/j.1600-0625.2000.009003192.x.pd
New flavonoids from the Saudi Arabian plant:Retama raetam which stimulates secretion of insulin and inhibits Ī±-glucosidase
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